Computer printers use a number of different techniques for applying ink to the paper. Many printers use a conventional typewriter ribbon, while other printers use thermal heads, and still others use lasers. One common species of computer printer uses ink jets, and the present invention is directed to a device for efficiently utilizing ink jet printers.
While ink jet printers have many advantages, one significant disadvantage is that the print head and ink reservoir are typically contained in a single disposable unit. For example, Hewlett-Packard of Vancouver, Wash., U.S.A. manufactures a line of ink jet printers that have disposable combination print head/ink reservoir cartridges. While the cartridges are of excellent quality, the requirement that a print head be supplied with each cartridge makes the cartridges unduly expensive. The useful life of a print head is many times the length of printing time provided by the ink reservoir, and thus a significant waste is incurred every time a spent cartridge is replaced simply because the ink has run out.
In addition, there are multicolor print cartridges that have three primary colors in separate reservoirs in each cartridge. Since it is rare that all three colors will simultaneously be spent, it is not unusual to throw away perfectly good cartridges having substantial supplies of two colors, but being empty for the third color.
For whatever reason, the manufacturers of the combination print head/ink reservoir cartridges have not seen fit to provide a way for the user to replenish the ink within the cartridges. In fact, the cartridges as presently supplied by, for example, Hewlett-Packard, have sonically welded cartridge halves that cannot be easily separated to enable reassembly after refilling one or more of the ink reservoirs inside.
Refilling ink cartridges with ink is a two-step process. First, some means must be provided to break open the cartridges, such as the ink cartridge opener described in my U.S. Pat. No. 5,546,830, the disclosure of which is herein incorporated by reference. Then, the reservoir must be refilled.
One drawback of prior ink cartridge openers is the lack of firm gripping of the cartridge during the somewhat delicate procedure of separating the top and bottom portions of the ink cartridge. In the opener described in my prior U.S. Pat. No. 5,546,830 base stand is configured to hold the cartridge vertically and upside down, applying opening force to the bottom of the cartridge while gripping the top portion in the base stand. While this has been an effective apparatus for opening cartridges, I have developed an improved ink cartridge opener with enhanced gripping and stability features described below. In addition, my improved opener has manufacturing advantages which will be described.
Thus, there presently exists a need for a device to enable the efficient and fool-proof separation of housing parts for an ink jet printer cartridge, such that internal ink reservoirs may be replenished and the cartridge reassembled for renewed use. The device should provide a simple and inexpensive ink cartridge opener that is efficient in manufacturing requirements and provides a solid grip on the printer ink cartridge during the opening procedure.